JP2017537819A - Multilayer synthetic resin lens manufacturing method - Google Patents

Abstract

For the production of a multilayer synthetic resin lens, a plurality of intermediate layers of synthetic resin material are sequentially formed in various cavities (23, 24, 25, 26, 27) relative to the base in the injection molding device (20), At least some of the cavities (23, 24, 25, 26) have a common first molding system (33) with a common material supply (35). Subsequently, the second molding system (34) forms at least one outer layer of synthetic resin material in another cavity (27), which performs the specific material supply and specific adjustment. [Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a multilayer synthetic resin lens in which a plurality of intermediate layers of a synthetic resin material are sequentially formed in different cavities with respect to a substrate in an injection molding apparatus.

  For some time, attempts have been made to make optical members, such as synthetic resin lenses, from synthetic resin instead of glass. This is because synthetic resins are easy to process and are particularly inexpensive. However, when the optical member or the synthetic resin lens has a relatively large thickness, for example, a biconvex lens, the synthetic resin cooling phase occurs more rapidly outside and at the end area than the center of the lens, and the heat is generated during this period. There may be a problem that mechanical deformation due to shrinkage and at least a change in optical characteristics of the lens occur. In order to avoid this, it is known to form the corresponding lens from two layers which are successively applied with a uniform synthetic resin material. For this purpose, for example, a substrate made of a synthetic material is injection molded in the first cavity. As soon as the substrate has sufficient strength, the injection mold is opened and the substrate is repositioned so that it is placed in the second cavity, and a second resin made of a synthetic resin material is formed in the cavity. Two layers are formed, where the first layer forming the substrate and the formed second layer are combined to form one uniform monolithic member. The member can be formed with third, fourth layers, etc. in corresponding cavities in subsequent working steps, all of which are made of the same synthetic resin material.

  In this case, it is particularly difficult to achieve an economical continuous production process. This is because the individual layers are different in size and thickness and therefore require different setting times and injection parameters. It has been found that the production of multilayer monolithic optical synthetic resin lenses is usually very time consuming and therefore costly.

An object of the present invention is to provide a method for producing a multilayer synthetic resin lens capable of producing a corresponding synthetic resin lens quickly and cost-effectively with good quality.

  This problem is solved by a method having the features of claim 1. In this method, first, a plurality of intermediate layers of synthetic resin material are sequentially formed in different cavities with respect to the substrate in one injection molding device, wherein at least some cavities have a common first with a common material supply. 1 molding system. The first molding system is usually a so-called hot channel, which is commonly used in synthetic resin and in particular thermoplastic injection molding equipment, and is thermal for other injection molds. Insulated and more highly temperature controlled.

  The recognition underlying the present invention is not important for the optical quality of the finished synthetic resin lens, but the manufacturing parameters when the intermediate layer is applied or formed, not for the optical properties of the synthetic resin lens. What is important is that the outer layer is to be formed and applied with optimal manufacturing parameters. According to the present invention, therefore, after the formation of the intermediate layer, an outer layer of synthetic resin material is preferably formed in the cavity of the second molding system, which is likewise a hot channel system. The second molding system has its own material supply and its own adjustment. The production parameters for injecting the outer layer of the lens by the inherent material supply and the inherent adjustment of the second molding system can on the one hand be precisely adjusted to the peripheral conditions in the production technology, on the other hand the production parameters are Depending on the manufacturing parameters for making or injecting the substrate.

  In an advantageous embodiment of the invention, the second molding system has a temperature adjustment device relating to the temperature of the synthetic resin material fed and injected and / or a pressure adjustment device for adjusting the pressure at which the synthetic resin material is injected into the cavity. To be.

  The synthetic resin lens has a carrier-like base portion, and is formed so that the intermediate layers sequentially overlap each other in the cavity of the first molding system. The base can be pre-made, but it can also be incorporated into the manufacturing process and formed in a single cavity that is preferably part of the first molding system in the first step. In this case, the base is preferably made of the same synthetic resin material as the intermediate layer subsequently formed in the first molding system.

  The intermediate layer can be sequentially formed on one side at the base and finally covered by the outer layer. This type of synthetic resin lens is bounded on the one hand by the base and on the other hand by the outer layer, but these are arranged on the light incident surface or the light exit surface, depending on the light incident direction.

Alternatively, it is also possible to inject at least some intermediate layers and preferably all intermediate layers in the form of two partial layers, respectively, on the base or on the opposite side of the material comprising at least one intermediate layer. is there. The first intermediate layer is injected to the base from opposite sides. In the next manufacturing process, the second intermediate layer is also formed on both sides of the first intermediate layer formed in the previous manufacturing process from opposite sides. This procedure is carried out until all the intermediate layers are formed in the form of two partial layers on the material produced in the previous manufacturing process on opposite sides. Finally, the outer layer is also formed on the material including the base layer and the intermediate layer formed on both sides from the opposite manufacturing sides from the opposite sides in the second molding system. In addition, the light emitting surface has partial layers of outer layers.

In an advantageous embodiment of the invention, all intermediate layers and possibly the base of the synthetic resin lens are also in the cavity of the first molding system and only the outer layer of the synthetic resin lens (on one or both sides) It is designed to be injected or formed in a molding system.

However, it is alternatively possible that the second molding system forms the outer layer of the synthetic resin lens and at least one intermediate layer below it.

Preferably, the base, all intermediate layers and the outer layer are made of the same synthetic resin material, but the outer layer can also be made of another or at least slightly different synthetic resin material.

Preferably, each cavity is provided with one injection channel, which fills the cavity with a respective amount of synthetic resin material. In this case, the pressure and / or temperature of the synthetic resin material can be controlled and adjusted independently of each other in at least some of the injection channels and preferably in all of the injection channels. In this case, the amount of synthetic resin material filled in the individual cavities of the first molding system is different from each other by a maximum of ± 10%, in particular by a maximum of ± 5% and particularly preferably by a maximum of ± 1%. can do. The starting point for the basic consideration in this case is to make the volume of the individual interlayers and thus the amount of synthetic resin material each filled to form the individual interlayers be the same or at least with very little difference It is. This allows the intermediate layer to be formed simultaneously in a continuous manufacturing process in the first molding system. This is because the amount of synthetic resin material required for each intermediate layer is very similar or identical and therefore has similar or identical injection molding parameters and in particular the setting time. Since the individual cavities have various shapes, the injection liquid synthetic resin material can be filled into the cavities by adjusting the injection pressure. For this purpose, according to the invention, it is possible to achieve optimum injection if the pressure of the synthetic resin material can be adjusted independently of one another in at least some injection channels of the first molding system, in particular in all injection channels. The process can be achieved.

  Preferably, the method according to the invention uses a so-called revolver injection mold, in which the two mold halves are pivotable relative to each other in the open position, so that the partial cavities respectively formed in the mold halves Are designed to form different cavities under various synergies. Corresponding revolver injection molds are known in the multilayer component injection molding process, and in the context of the present invention, the only synthetic resin in the order of the optical synthetic resin lens material in a thin intermediate layer of about 2-3 mm. Used to form from material.

  The material is then formed on the outer layer in the second molding system, with the first molding system and the second molding system being formed in a common injection mold but independent of each other. Can do.

  In an advantageous embodiment of the invention, the injection channels leading to the individual cavities of the first molding system provide synthetic resin material from a common supply channel. In the common supply channel, the synthetic resin material is preferably under a predetermined pressure that is higher than the pressure when the synthetic resin material is injected into the individual cavities. The pressure drop between the pressure in the supply channel and the original injection pressure into each cavity reduces the pressure of the synthetic resin material in the injection channel, and for the intermediate layer formed against or within each cavity. This is achieved by adapting to the optimum value. In a possible embodiment of the present invention, this is achieved by adjusting the pressure of the synthetic resin material in the cavity, for example, by reducing the cross-sectional area of each injection channel where an adjustable throttle location is located in each injection channel. .

  In particular, when forming a convex synthetic resin lens by sequentially filling various intermediate layers, each layer has a larger area than its lower layer. If the amount of synthetic resin provided for the formation of the individual intermediate layers is the same or at least about the same, the layers will change. In this case, according to the present invention, the individual intermediate layers of the synthetic resin lens are formed with different layer thicknesses, and at this time, the layer thickness of the (n + 1) th layer is less than the layer thickness of the previously formed nth layer. Has proven to be advantageous.

  Further details and features of the invention will be apparent from the following description of embodiments with reference to the drawings.

FIG. 1 is a cross-sectional view of a synthetic resin lens formed in a layer shape according to the first embodiment. FIG. 2 is a cross-sectional view of a synthetic resin lens formed in layers according to the second embodiment. FIG. 3 is a schematic view of an injection molding apparatus for producing a multilayer synthetic resin lens by the method of the present invention. FIG. 4 shows a modification of the injection molding apparatus according to FIG.

  FIG. 1 shows a cross section of a multilayer synthetic resin lens according to the first embodiment. The synthetic resin lens 10 has a carrier-like base portion 11 on which a plurality of upper and lower layers are formed. On the base 11, a first intermediate layer 12 is injected on one side. A second intermediate layer 13 is applied on the first intermediate layer 12, and this layer is covered by a third intermediate layer 14. On top of this, a fourth intermediate layer 15 covering the third intermediate layer 14 is further applied. Finally, an outer layer 16 covering all the intermediate layers 12, 13, 14, 15 is applied, but this layer smoothly transitions to the base 11. Since all the layers are made of the same synthetic resin material, one monolithic body formed in multiple layers made of a uniform material is formed.

  According to FIG. 1, since all the layers are formed only on one side on the base 11, the synthetic resin lens 10 is bounded on the one hand by the base 11 on the one hand and by the outer layer 16 on the other hand. FIG. 2 shows a variant embodiment in which each layer is formed on the base 11 on both sides. In the embodiment shown in FIG. 2 of the synthetic resin lens 10, as in the first embodiment, one carrier-like base portion 11 is provided, and this base portion has a first intermediate layer 12 on both sides in the first step. The synthetic resin material is applied. These partial layers of the first intermediate layer 12 arranged on opposite sides of the base 11 are each covered with a corresponding partial layer of the second intermediate layer 13. Subsequently, partial layers of the third intermediate layer 14 and the fourth intermediate layer 15 are sequentially applied to both sides. Finally, since the outer layer 16 is injected on both sides of the base 11 and the material formed from these intermediate layers, the synthetic resin lens 10 has four intermediate layers 12, 13, 14, 15 and an outer layer 16 covering the outside.

  FIG. 3 is a schematic view of the injection molding apparatus 20, and the synthetic resin lens 10 shown in FIG. 1 or 2 is manufactured by the method of the present invention. The injection molding apparatus 20 includes a mold part 21 in which a plurality of cavities, that is, a first cavity 22, a second cavity 23, a third cavity 24, a fourth cavity 25, and a fifth cavity 26 are provided. It is formed. In the embodiment shown, these cavities are arranged side by side in a row, but it is also possible to arrange the cavities on the circumference of a rotatable mold part, which is rather advantageous.

  In the production of synthetic resin lenses, the cavities are normally closed by another mold part (not shown), and all the cavities 22, 23, 24, 25, and 26 are filled with the same synthetic resin material at the same time in one shot. Is done.

  The injection molding apparatus 20 includes a first molding system 33 and a second molding system 34 that is completely separate from the first molding system 33, each of which is preferably a so-called hot channel system. The first molding system 33 includes cavities 22, 23, 24, 25, 26 of the mold part 21.

The synthetic resin material is in a synthetic resin storage tank 29, which is schematically shown, from which a common supply channel 35 leads to the cavities 22, 23, 24, 25, 26. From the supply channel 35, an injection channel 36 unique to each cavity is branched. A pressure adjusting device 32 is arranged in each injection channel 36 in the form of an adjustable throttle. In addition, a temperature adjusting device 31 is disposed in each injection channel 36, whereby the temperature of the synthetic resin material in each injection channel 36 can be adjusted.

  Further, the injection molding apparatus 32 includes a second molding system 34 having a sixth cavity 27 formed in the mold portion 28, in which an injection channel 36 is provided from the synthetic resin storage tank 30. The synthetic resin material can be injected via Similarly, a temperature adjusting device 31 and a pressure adjusting device 32 are arranged in the injection channel 36.

  The first molding system 33 and the second molding system 34 can be formed in one common injection mold, but each molding system can also have its own injection mold. However, what is important here is that the molding systems 33, 34 can be adjusted and operated independently of each other.

  Hereinafter, the method for producing the synthetic resin lens of the present invention will be described in detail with reference to FIG.

  In the initial stage of the manufacturing process, the synthetic resin material is injected only into the first cavity 22 of the first molding system 23 and the other cavities are still closed. In the first cavity 22, a carrier-like base 11 is formed. Subsequently, the mold is opened and the mold parts are adjusted relative to each other so that the base 11 previously formed by the first cavity 22 is now in the second cavity 23. After the mold part is closed, the synthetic resin material is injected into the second cavity 23, whereby the first intermediate layer 12 is formed (on one side or both sides) on the base 11, thereby forming a so-called first material. The At the same time, the synthetic resin material is again injected into the first cavity 22, thereby forming another base 11. Another cavity is still closed in this case.

  Subsequently, the mold part is reopened and adjusted relative to each other so that the first material including the base 11 and the first intermediate layer 12 is now in the third cavity 24 and first the first cavity. The base 11 formed in 22 is now placed in the second cavity 23. The mold part is closed again, and the synthetic resin material is injected into the first, second and third cavities 22, 23 and 24. In this case, another base 11 is formed in the first cavity 22. In the second cavity 23, the first intermediate layer 12 is formed on the previously formed base 11, and in the third cavity, the first material having the base 11 and the first intermediate layer 12 is the second material. The intermediate layer 13 is formed, whereby a so-called second material is formed. The fourth cavity 25 and the fifth cavity 26 are still closed in this case.

  Subsequently, since the mold part is opened again and relatively adjusted, the second material composed of the base part 11, the first intermediate layer 12, and the second intermediate layer 13 is disposed in the fourth cavity 25. At the same time, the third cavity 24 has a first material comprising the base 11 and the first intermediate layer 12 previously made in the second cavity 23. Within the second cavity 23 is the base 11 previously formed within the first cavity 22. The mold part is closed again, and a synthetic resin material is injected into each cavity. This process continues accordingly.

  In this way, a single material is formed in the first molding system 33 in five manufacturing steps, and this material has a carrier-like base 11 on which one side in the example of FIG. In this example, four intermediate layers 12, 13, 14, and 15 are arranged on both sides so as to cover each other. In this case, the base 11 and all the intermediate layers 12, 13, 14, and 15 are made of the same synthetic resin material. Become. In the next manufacturing step, this material is removed from the first molding system 33 and filled into the sixth cavity 27 of the second molding system 34, where it is on one side in the example of FIG. 1 and on both sides in the example of FIG. An outer layer 16 is formed thereon, with the synthetic resin material used for the outer layer 16 being removed from the synthetic resin reservoir 30 of the second molding system 34. This material can be the same synthetic resin material as the synthetic resin material of the first molding system or a different synthetic resin material.

  The post-application injection process after the outer layer is completed, and the synthetic resin lens is formed in a layer shape. At this time, further processing can be performed as necessary.

  Each layer forming the synthetic resin lens is bonded to one monolithic body, and no boundary surface is seen between the respective layers.

  Since the outer layer 16 is made of an independent second molding system 34, the production parameters useful for the production of the outer layer 16 can be optimally adjusted to the requirements of the outer layer 16, while the base 11 and the intermediate layer. Are produced in the first molding system 33 with a combination of parameters that allow for rapid production of good quality materials.

FIG. 4 shows an injection molding apparatus 20 which is a modification of the injection molding apparatus of FIG. The injection molding apparatus 20 according to FIG. 4 is different from the injection molding apparatus of FIG. 3 in that the final intermediate layer 15 and the outer layer 16 are sequentially formed in the second molding system 34, whereas the first molding system 33 is merely The difference is that the base 11 and the three intermediate layers 12, 13, 14 are formed. For this purpose, the mold part 28 of the second molding system 34 is formed with a fifth cavity 26 and a sixth cavity 27, which are fed from the synthetic resin storage tank 30 to the supply channel 37 and each of the cavities. A synthetic resin material can be supplied through the injection channel 36. Each injection channel 36 is provided with the temperature adjusting device 31 and the pressure adjusting device 32 as described above. The material transferred between the first molding system 33 and the second molding system 34 is in this case a carrier-like base 11 and three intermediate layers applied on one side in the example of FIG. 1 and on both sides in the example of FIG. 12, 13, and 14. After the material is transferred to the second molding system 34, the final intermediate layer 15 is formed in the fifth cavity 26 there, and subsequently the outer layer 16 is formed in the sixth cavity 27 in the next manufacturing step. Formed.

DESCRIPTION OF SYMBOLS 10 Multilayer synthetic resin lens 11 Base 12 Intermediate layer 13 Intermediate layer 14 Intermediate layer 15 Intermediate layer 16 Outer layer 20 Injection molding device 21 Mold part 22 Cavity 23 Cavity 24 Cavity 25 Cavity 26 Cavity 27 Cavity 28 Mold part 29 Synthetic resin storage Tank 30 Synthetic resin storage tank 31 Temperature adjusting device 32 Pressure adjusting device 33 Molding system 34 Molding system 35 Supply channel 36 Injection channel 37 Supply channel

Claims (15)

  A plurality of intermediate layers (12, 13, 14, 15) of synthetic resin material are sequentially placed in various cavities (23, 24, 25, 26) relative to the base (11) in one injection molding device (20). Formed and at least some of the cavities (23, 24, 25, 26) have a common first molding system (33) with a common material supply and subsequently synthesized by a second molding system (34). A multilayer synthetic resin in which at least one outer layer (16) of resin material is formed in one cavity (27) so that the second molding system (16) provides specific material supply and specific adjustments. Manufacturing method of lens (10).   2. Method according to claim 1, characterized in that the adjustment of the second forming system (16) comprises a temperature adjusting device (31) and / or a pressure adjusting device (32).   3. The method according to claim 1, wherein only the outer layer (16) of the synthetic resin lens (10) is formed by the second molding system (34).   3. The outer layer (16) of the synthetic resin lens (10) and the at least one intermediate layer (15) below it are formed by the second molding system (34). the method of.   The method according to one of the preceding claims, characterized in that the base (11) is made in the first step with one cavity (22) of the injection molding device (20).   Method according to claim 5, characterized in that the cavity (22) forming the base (11) is part of the first molding system (33).   7. The method according to claim 1, wherein the base (11) and the intermediate layer (12, 13, 14, 15) are made of the same synthetic resin material.   8. The method according to claim 1, wherein the outer layer (16) is made of the same synthetic resin material as the intermediate layer (12, 13, 14, 15).   At least some intermediate layers (12, 13, 14, 15) and / or outer layer (16) are in the form of two partial layers base (11) or base (11) and at least one intermediate layer (12, 13). , 14, 15) from the opposite side of the material.   Each cavity (22, 23, 24, 25, 26, 27) is provided with an injection channel (36) for filling the cavity with a synthetic resin material, and the pressure and / or temperature of the synthetic resin material is at least several injection channels ( The method according to one of claims 1 to 9, characterized in that they are adjusted independently of each other in 36).   11. The amount of synthetic resin material filled in the individual cavities (22, 23, 24, 25, 26) of the first molding system (33) differs from each other by a maximum of ± 10%. The method according to one of the above.   12. The amount of synthetic resin material filled in the individual cavities (22, 23, 24, 25, 26) of the first molding system (33) differs from each other by a maximum of ± 5%. Method.   13. The amount of synthetic resin material filled in the individual cavities (22, 23, 24, 25, 26) of the first molding system (33) differs from each other by a maximum of ± 1%. Method.   13. Method according to one of claims 10 to 12, characterized in that the pressure of the synthetic resin material is adjusted independently of each other in all injection channels (36).   Each intermediate layer (12, 13, 14, 15) of the synthetic resin lens (10) is formed with various layer thicknesses, and the layer thickness of the (n + 1) th layer is the layer of the nth layer formed first. 15. A method according to claim 1, wherein the thickness is less than the thickness.

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